The teens partied so hard at the mansion, which is under construction, that they reportedly caused $70,000 in damage.
The hashtag #MansionParty began trending on social media and more than 200 cars were parked in the area of the party.
The police sent more than 60 squad cars and a K-9 unit to break up the rowdy gathering.
"I have seen something like this, in the movies, but never in real life," a 16-year-old partygoer told the Record. “There were hundreds of people here. Some people were climbing over ladders and smashing the windows. Some were drinking. Everyone wanted to get inside."
There were no reported injuries at the party and no one was arrested for trespassing. Some people were arrested for assaulting officers and public intoxication.
"We want to make the public aware that social media may not be the best place to advertise the party, simply because we're not really aware of just how far-reaching social media really is," Const. Thomas Ruttan told the Brampton Guardian.